Safety-shutter.



F. MCMILLAN.

SAFETY SHUTTER.

wrucmon FILED JULY 13, 1am. RENEWED MAY 14, 1919.

Patented Dec. 30,1919.

2 SHEETS-SHEET i.

l' McMILLAN SAFETY SHUTTER.

APPLICATION FILED JULY 13, 1918. RENEWED MAY 14,1919.

'1 ,326,409. Patented Dec. 30,1919.

2 SHEETSSHEET 2- UNITED STATES PATENT OFFICE.

FRANK MGMILLAN, OF GLENELLYN, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,TO NATIONAL DROP HEAD PROJECTOR COMPANY, OF FOND DU LAC, WISCONSIN, ACOR- PORATION OF WISCONSIN.

SAFETY-SHUTTER.

Specification of Letters Patent.

Patented Dec. 30, 1919.

Application filed July 13, 1918, Serial N0. 244,709. Renewed May 14:,1919. Serial No. 297,159.

To all whom it may concern:

Be it known that I, FRANK MOMILLAN, a citizen of the United States ofAmerica, and a resident of Glenellyn, in the county of Dupage, State ofIllinois, have invented certain new and useful Improvements inSafety-Shutters, of which the following is 'a specification.

This invention relates to motion picture machines of the intermittentfilm feeding type, in which the light passage is closed by asupplementary shutter operatively con nected to the film feedingmechanism and adapted to automatically open the light passage when apredetermined speed of rotatlon in said mechanism is reached, thepurpose being to prevent an ignition or firing of the picture film,which is of frequent occurrence, when said film passes slowly through amachine not provided with means toshield the film during such slowmovement. And the present improvement has for its ob ect:

To provide a simple and efficient structural formation and associationof the light controlling mechanism of a motion picture machine, whereinthe shutter performing the usual periodic interruption of the lightpassage, is adapted to automat cally operate a supplementary shutterforming a barrler in said light passage and effect an opening of saidsupplementary shutter when a predetermined speed of rotation of themechanism is reached, all as will hereinafter more fully appear.

In the accompanying drawings Figure 1 is a central longitudinalsectional elevation of an intermittent film feeding mechanism having thepresent invention applied.

Fig. 2 is a detail side elevation of the operating mechanism of thesupplementary or safety shutter.

Fig. 3 is a detail transverse section on line X --X Fig. 2, showingtheprimary shutter and its operative connections to the supplementary orsafety shutter.

Fig. 4 is an enlarged detail transverse section on line X X Fig. 1,illustrating the detail construction of the primary light shutter.

Like reference numerals indicate like parts in the several views.

Referring to the drawings, 1 designates a part of the front wall or ofthe main casing of a motion picture machine, and upon which thesupporting housing or frame 2 of the intermittent film feeding mechanismis carried, as usual in the present class of machines.

3 designates the usual aperture plate behind which the picture film hasintermittent vertical movement through theusual intermittently actuatedsprocket drum 4, the said film being guided and held to proper verticaltravel by a hinged gate 5 properly apertured for the passage of light.

6 designates the usual optical objective of the machine, arranged inline with the light aperture of the plate 3 aforesaid.

7 designates the primary light controlling shutter, arrangedintermediate of the aperture plate 3 and the objective 6 and having acarrying shaft 8 provided with a gear wheel 9 forming a part of thetrain of gearing by which motion is imparted to the film feedingmechanism, light shutter and other parts, so that the same will operatein unison.

The present improvement involves in connection with a film feedingmechanism and primary shutter of a motion picture machine, such as abovedescribed, a structural formation and association of parts as follows 10designates a depending supplementary or safety shutter hinged at itsupper end to the film gate 5 by a horizontally arranged pivot rod 11,and normally depending at the backof the aperture plate 3, and in thepath of the lightbeams passing to the aperture of said plate, toentirely cut off said rays from the picture film and prevent a firing ofthe same. Such position of the safety shutter 10 prevails untilapredetermined speed of rotation of the operating mechanism is attainedwhen said shutter is automatically moved out of said light path, andpermits the passage of the light beams to the picture film and theobjective 6, of the machine.

12 designates a swinging arm or member secured to one end of the pivotrod 11 of the safety shutter, and preferably of the ring a stop throator abutment 14 adapted to limit the extent of the swinging motion whichis imparted to said arm or member 12 by the automatic operatingmechanism hereinafter described.

In the present improvement the primary shutter 7 consists of a pair ofopposed blades, segmental in cross-section, disposed in parallelrelation to each other and to the axis of rotation of the shutter, andhaving at one end carrying arms 7 which are pivoted at opposite sides ofthe axis of rotation in a carrying hub 15 on the operating shaft 8 ofthe shutter.

16 designates friction jaws on the carrying arms 7 aforesaid intangential relation to the pivots of said arms and adapted forfrictional engagement with a spindle now to be described.

17 designates a loose spindle arranged centrally in an axial bore of theshutter carrying shaft 8 and held from longitudinal movement by end stopcollars, as shown, or other like means.

18 designates a radial arm or finger carried on one end of the spindle17, with its outer end adapted to have bearing against the curved edgeof the aforesaid swinging arm or member 12 of the safety shutter, toimpart a swinging movement to said arm 12 and a corresponding rising oropening movement to the safety shutter.

The operation of the present safety shutter mechanism is as follows Inan initial operation or starting of the motion picture mechanism, theprimary shutter will have a slow rotation and the friction jaws 16 willbe out of operative engagement with-the loose spindle 17 and willrevolve independent of said spindle. As the speed of rotation of theprimary shutter nears the required or predetermined degree, the shutterblades, under centrifugal influence will have outward pivotal movementon the pivots of their arms 7 "and bring the friction jaws 16 intolimited frictional engagement with the loose spindle 17 to impart tosaid spindle a partial rotation in the direction of the rotation of saidjaws. The limited frictional engagement of the jaws 16 just mentionedpermits of independent rotation of said friction jaws after the requiredpartial rotation of the spindle 17 has been effected, and during saidindependent rotation of the friction jaws, the same will act to retainsaid spindle 17 at the described point of partial rotation.

In the above described partial rotation of the loose spindle 17, acorresponding rocking motion is imparted to the arm 18, and from thesame to the swinging arm or member 12 and to the safety shutter 10,which is moved from a closed position indicated in full lines in Fig. 1,to an open position ining movement of the shutter.

dicated in dotted lines in said Fig. 1. With a stoppage or slowing downin the rotation of the mechanism, the shutter 10 drops at once to itsclosed position above described.

In the above described opening movement of the safety shutter theoperating arm 18 progressively decreases the distance of its bearingpoint from the axis of the pivot rod 11 of the safety shutter and uponthe curved bearing surface of the ring shape arm 12, to effect aprogressive increase in the open- This has been found of value inattaining an accurate and efficient automatic operation of themechanism.

Having thus fully described my said invention what I claim as new anddesire to secure by Letters Patent, is

1. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, the primaryshutter having blades adapted to move under centrifugal influence andoperatively connected to the safety shutter, substantially as set forth.

2. The combination of a primary shutter and a secondary safety shutterdisposed in. the light path of a motion picture machine, the primaryshutter having a pair of blades arranged in approximately parallelrelation to each other and to the axis of rotation and hinged at one endto a carrying hub, and operative connections between said hinged bladesand the safety shutter, substantially as set forth.

3. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, the primaryshutter having a pair of blades arranged in approximately parallelrelation to each other and to the axis of rotation and having end armsby which they are pivoted to a carrying hub, a loose spindle associatedwith said carrying hub and adapted for frictional engagement with theaforesaid end arms, and operative connections between said spindle andthe safety shutter, substantially as set forth.

4. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, the safetyshutter having a supporting pivot rod, and the primary shutter havingblades adapted to move under centrifugal influence and operativelyconnected to pivot rod of I the safety shutter, substantially as setforth.

5. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, the safetyshutter having a supporting pivot rod, and the primary shutter having apair of blades arranged in approximately parallel relation. to eachother and to the axis of rotation and hinged at one end to a carryinghub, and operative connections between said hinged blades and theaforesaid pivot rod of the safety shutter, substantially as set forth.

6. The combination of primary shutter and a secondary safety shutterarranged in the light path of a motion picture machine, the safetyshutter having a supporting pivot rod, an operating member secured tosaid pivot rod and having a ring shape, the primary shutter havingblades adapted to move under centrifugal influence and operativelyconnected to the aforesaid operating member of the safety shuttersubstantially as set forth.

7. The combination of a primary shutter and a secondary safety shutterarranged in the light path of a motion picture machine, the safetyshutter having a supporting pivot rod, an operating member secured tosaid pivot rod, said operating member having a ring shape and providedwith a peripheral guard finger, the primary shutter having bladesadapted to move under centrifugal influence and operatively connected tothe aforesaid operating member of the safety shutter, substantially asset forth.

8. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, a pivot rodforming a support for the safety shutter, an operating member on saidpivot rod, the primary shutter comprising a pair of hinged bladesadapted to move under centrifugal influence, a carrying hub to whichsaid blades are hinged, a loose spindle associated with said hub andadapted for frictional engagement with the shutter blades, and an armcarried by said loose spindle and having engagement with the operatingmember on the pivot rod of the safety shutter, substantially as setforth.

9. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, a pivot rodforming a support for the safety shutter, an operating member on saidpivot rod and having a ring shape, the primary shutter comprising a pairof hinged blades adapted to move under centrifugal influence, a carryinghub to which said blades are hinged, a loose spindle associated withsaid hub and adapted for frictional engagement with the shutter blades,and an arm carried by said loose spindle and having engagement with theaforesaid operating member on the pivot rod of the safety shutter,substantially as set forth.

10. The combination of a primary shutter and a secondary safety shutterdisposed in the light path of a motion picture machine, a pivot rodforming a support for the safety shutter, an operating member on saidpivot rod, said operating member having a ring shape and provided with aperipheral guard finger, the primary shutter comprising a pair of hingedblades adapted to move under centrifugal influence, a carrying hub towhich said blades are hinged, a loose spindle associated with said huband adapted for frictional engagement with the shutter blades, and anarm carried by said loose spindle and having engagement with theaforesaid operating member on the pivot rod of the safety shutter,substantially as set forth.

Signed at Santa Cruz, Cal, this 3rd day of June 1918.

' FRANK MoMTLLAN.

